Project Abstract This training program in mechanisms of viral infection will train 6 predoctoral students and 4 postdoctoral fellows per year. The goal of this training grant is to provide students who 1) are well trained in the study of mechanisms of viral replication, 2) can investigate human viruses causing disease, such as the human immunodeficiency virus and herpes viruses, 3) can investigate new antiviral compounds and vaccines to prevent or treat viral diseases, 4) can study viruses that are emerging threats to human health, and 5) can use viruses to probe the cellular and molecular biology of prokaryotic and eukaryotic cells. Nearly all of the predoctoral applicants will have an undergraduate education in biology or chemistry. All of the predoctoral trainees will be graduate students in the Program in Virology, an inter-faculty degree-granting program. The laboratories of the training faculty are located at Harvard Medical School and affiliated hospitals, Harvard School of Public Health, Dana-Farber Cancer Institute, Children's Hospital, and the Harvard University Fairchild Laboratory in Cambridge. The Program in Virology students pursue a broad biological program of study with courses in virology, molecular biology and genetics, biochemistry, cell biology and immunology. These students will also attend seminars, research meetings, and perform 3 laboratory rotations. Faculty curriculum advisors will provide guidance for the students throughout their training, and they will choose their advisors from the Program in Virology faculty. Students will take a preliminary qualifying examination during their second year, and within 6 months form a dissertation advisory committee to provide advice on the progress of their research. Upon successful completion and defense of the dissertation, the student will be awarded a Ph.D. degree in virology. Postdoctoral training takes place in the laboratories of the training faculty. Consistent with the specialized nature of postdoctoral training, the primary program will be designed by the faculty advisor. This training program is designed to augment that training by engaging the postdoctoral fellow in virology program retreats, courses, and seminars. Postdoctoral trainees will form a postdoctoral advisory committee that will meet at least annually to evaluate research and career paths. Predoctoral and postdoctoral trainees will participate in a training program in the ethical conduct of science. An active and previously successful program by the training faculty and Division of Medical Sciences is described for the recruitment of underrepresented minority trainees.